Call-distributing system.



L. POL'NKOWSKYi CALL DISTHIBUHNG SYSTEM.

APPLICATION FILED MAIL. Ian.

Patented Apr. 8,1919.

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cm DISTRIBUTING SYSTEM, APPLICATION FILED MARVIN, 19H. 1 ,299,606, Patented Apr. 8, 1919.

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UNITED STATES PATENT OFFICE.

LIPA. POLINKOWSKY, OF LONDON, ENGLAND, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

CALL-DISTRIBUTING SYSTEM.

Patented Apr. 8,1919.

Application filed March 24, 1917. Serial No. 157,095.

To all whom it may concern:

Be it known that I, LIPA POLINKOWSKY, a subject of the Emperor of Russia, residing at London, England, have invented certain new and useful Improvements in Call-Dis tributin Systems, of which the following is a full, c ear, concise, and exact description.

This invention relates to a call distributing system for telephone exchanges and more particularly. to systems in which calls are automatically extended to an operators position, and, depending upon the busy or idle condition of the connecting apparatus thereat, are associated with such connecting apparatus. It has been heretofore proposed to distribute calls to operators positions and to prevent the distribution of such calls to an operators position as long as an operator at such position is engage It has also been proposed to distribute calls to operators posltions which are maintained busy for a predetermined period of time, irrespective of Whether or not the o rator is engaged, so that a subse uent cal may be distributed to a position a er a definite time interval which is in practice slightly less than the time which the operator under normal conditions utilizes in performing her duties in connection with a call.

It is an object of the present invention to obtain the advantages of both of the schemes outlined above, that is, to provide for the distribution of calls to a position at definite and predetermined intervals, which intervals, however, may be automaticall varied in case, due to some unusual condition arising at the operators position, the operator has not disposed of a preceding call within the usual time. Therefore, in accordance with a feature of the invention, means are provided so that after a call is extended to an operators position, means is made operative to prevent the distribution of another call to that position for a predetermined time interval which may be slightly less than the time interval utilized by an operator in extending a call, and also provision of further means which is brought into opera tion in case the timeconsumed by the operator in extending the callis longer than the normal. interval, which will modify the firstmentioned means so that the o erators position is maintained busy'to subsequent calls for a longer time interval than normal. For example, if a call is extended to the operators position, timing means is brought into operation to maintain the position busy for a predetermined time interval. When a second call comes in, if the first call is being attended to at the operators position in a normal manner, such second call may be distributed to the position after a predetermined time interval. On the other hand, if the first call is not attended to in the normal manner, the operation of the timing is modified so that a longer predetermined time interval will elapse before the second call can be associated with the operators active ap paratus. F urthermone, if, after the elapse of this longer interval still another call is extended to the operators position, and if not only one but two calls are still unconnected to the operators connecting equipment, the o eration of the timing means is again modi ed to still further prolong the time interval before the busy guard is removed from the operators position.

Further features of the invention will sufficiently appear from the specification and drawings in which Figures 1 and 1 when placed side by side diagrammatically illustrate the complete system.

Referring to Fig. 1, 3 represents a telephone line terminating in a group of first line finders, one of which is indicated at 4, and having associated therewith the usual line relay 5, energized upon the initiation of a call to place selectable potential in the usual manner upon the test terminal 6 of such line Where it appears in the first line finder 4, and energizing the pilot or starting relay 7 commonto the group of lines in which such line appears. The energization of the relay 7 closes a circuit for the power magnets 8 of all of the first line finders of the group indicated which are idle, that is, of which the relays 9 and 10 are denergized. All of such idle first line finders thereupon start in motion to select and seize the calling line in the usual manner. Immediately that the brush 11 of one of such line finders makes contact with the terminal 6, the relay 12 is energized lacing a busy guard upon such terminal 6 y the closure of the circuit to ground through the low resistance righthand winding of such relay 12 and when the interrupter 13 of such line finderis opened as the brushes of such line finder are centered upon the terminals of the calling line, the shunt through such interrupter around the relay 9 is removed and such relay energizing, the circuit of the ower magnet 8 is opened and the circuit 0 the holding net 14 of such line finder is closed and tie line finder brought positively to a stop with its brushes in contact with the terminals of the calling line. The energization of the relay 9 has closed a circuit in series with the circuit for the holding magnet 14 list starting a ilot relay 15 common to the group of trunk lines terminating in a given set of second line finders 16.

Assuming that the operator to whose position the connecting circuit 17 is individual is idle, a circuit will be established by the energizetion of such relay 15 over the sequence switch contact 72, sequence switch contact 62 to the relays 18 of all such as are idle of said connecting circuits whose second line finders 16 of such opera-tors position have access to the first line finder taken for use.

Before proceeding further it will be noted that all of the sequence switch contacts shown in the upper part of Fig. 1 form a part of and are operated by the sequence switch 60 shown to the right of Fig. 1. Those sequence switch contacts shown within the dotted area in which the sequence switch is shown. form a part of and are operated by such sequence switch. Similarly, those sequence switch contacts shown within the area delimited by the dotted line in which the sequence switch 80 is shown form a part of and are operated by such sequence switch, and those shown within the area in which the sequence switch 90 is shown form a part of and are operated by such sequence switch. These switches are of well-known construction and their mode of operation being known will not be described in detail herein.

Upon the energisation of the relay 18 a circuit is closed over its armature and front contact, armature and back contact of the relay 19, sequence switch contact '63, to the power magnet $9 of the second line finder 1.6 to which the connecting circuit 17 is connected. uch second line finder thereupon starts in motion searching for the selectable oten-tial which has been placed upon the est terminal 21 of the trunk 22, extending from the first line finder 4: by the energize.- .ti-on of the relay 9 in the usual manner. As soon as the test brush 23 reaches the terminal '21, a circuit is completed over the sequence switch contact 65, right-hand winding of the relay 24, sequence switch contact 8% to energize such relay 24 whichthereupon places the usual busy guard upon the terminal 21 b the closure of the low resistance circuit through its left-hand winding. soon as the "brushes of the'line finder 16 are centered upon the terminals of the trunk 22 the shunt circuit around the relay 19 is opened by the interrupter 25, and such relay 19 is energized, opening the circuit of the power magnet 20 and closing in the usual manner the circuit of the holding magnet 20 of the line finder 16 to stop such line finder in the usual manner with its brushes properly centered upon the terminals of the trunk 22. The of the relay 19 also closed circuits to energize the relay 26 and the power magnet of the sequence switch 60. Sequence switch 60 is driven from its first or normal position and under the influence of the local sequence switch contact 61 moves into its fourth position. The energisation of the relay 2 6, which is main tained until the sequence switch 60 has moved out of its second position, closes a circuit over its armature and front contact and the sequence switch contact 83 to energize the power mag-net of the sequence switch 80, which, together with the sequence switches 79 and 90 and the relays 27 and 28, are common to the position of the operator on which the connecting circuit 17 appears. The power magnet of the sequence switch 80 being energized in its first or normal position, such sequence switch moves under the control of its local contact 81 into its fourth position. The movement of the sequence switch 80 out of its first position opens the sequence switch contact 82 and the sequence switch contact 83 top. 011 coming into its second position the circuit was closed over the sequence switch contact 84 and the sequence switch contact 73 to drive the sequence switch 70 out of its first and, under the control of its local contact 71, into its twelfth position. When the sequence switch 89 comes into its fourth position a circuit is closed over the sequence switch contact 85 and the sequence switch contact 92 top to starii the sequence switch 90 in motion, which, since its local contact is only open in its first or normal position, will immediately make a complete revolution. As such sequence switch 90 passes though its eighteenth position, just before returning to its first or normal position, the sequence switch contact 92 bottom is closed and a circuit extends from the uence switch contact 85, over sequence switc contact 92 bottom, to drive'the sequence switch 80 into its fifth position.

When the sequence switch 60 moved into its fourth position circuits were established in 'li'atent No; 1,1675%; to F R. McBerty. Smoeit hasbeen assumed that this 0 erator is'idle such registering and control ing' equipment has been found and seized before the sequence switch 80 reached its fifth position after the complete revolution of the sequence switch 90 and the sequence switch 60 has, therefore, been driven out of its fifth position in the known manner opening the sequence switch contact 66 included in the circuit of the switch 29 and consequently deenergizing the relays 27 and 28 in series therewith. A circuit, therefore exists when the sequence switch 80 comes into its fifth position over the sequence switch contact 86 top and back contact of the relay 28 to drive the sequence switch 80 into its eighth position. In this position again a circuit is closed to drive the sequence switch 80 into its tenth position, this circuit including the sequence switch contact 86 bottom and the back contact of the relay 27. On coming into its tenth position, the sequence switch 80 closes the sequence switch contact 85 which again starts the sequence switch 90 to make a complete revolution. As sequence switch 90 is again passing its eighteenth p0 sition a circuit is closed over sequence switch contact 85 and 92 bottom to drive the sequence switch 80 into its eleventh position. The sequence switch 90, therefore, when it reaches its first or normal position, finds the circuit connection closed over the sequence switch contacts 85 and 92 top and starts on a third complete revolution. Near the completion of the third revolution of the sequence switch 90 the closure of the sequence switch contact 92 bottom again causes the energization of the power magnet of the sequence switch 80 which drives this' sequence switch out of its eleventh position and passing through its twelfth, thirteenth, etc., positions, such sequence switch returns to its first or normal position.

It will be observed that immediately upon the seizure of the trunk 22 whereby a call is extended to the operators position, the apparatus of which is shown, and the consequent energization of the relays 19 and 26,

the sequence switch 80 started in motion and immediately drove the sequence switch 7 0 out of its first or normal position. This caused the opening of the sequence switch contacts 72, 72, and 72* which will be maintained open until the sequence switch 70 returns to its first or normal position. These sequence switch contacts as has been before noted are included in the common starting circuits of several groups of the connecting circuits located upon the position of the operator in question. So long, therefore, as such sequence switch contacts remain open, no calls may be extended to such operators position and none of the second line finders individual to the connecting circuits appearing upon such operators position may be set in motion. \Vhen, however, the time interval necessary for the operation of the sequence switch 80 into its thirteenth position, which time interval includes definitely the time required for the sequence switch 90 to make three complete revolutions, has elapsed, the sequence switch will be driven out of its twelfth position by the closure of the sequence switch contact 84 bottom and such sequence switch 70 will leave its twelfth position and then, without stopping, move into its first or normal position in which the sequence switch contacts 7 2, 72 and 72* are closed. At this time, further incoming calls which have been extended to trunks such as 22 accessible to the set of second line finders connected to connecting circuits such as 17 which appear upon this operators position, will cause the operation of such second line finders 16 in the manner hereinbefore de scribed to extend such incoming call to a connecting circuit upon such operators po sition. It will, therefore, be seen that when one call has been extended to the operator's position such operators position is maintained busy to all further incoming calls until after the passage of a definite interval. of time as predetermined by the adjustment, arrangement and construction of the se quence switches 70, SO and 90. After such interval of time has passed the busy guard is removed from such operators position and a second call may be extended thereto. When the second call has been extended to a connecting circuit of such operators position, as has been described, and in consequence thereof energized the relays l9 and 26 individual to the connecting circuit and second line finder to which such call has been extended, the timing apparatus is again started in motion opening the sequence switch contacts 72, 72' and 72 and placing a busy guard upon the position and maintaining such busy guard for the predetermined interval of time, after which they are again closed and a still further call may be extended to such operators position.

It will be recalled that when the sequence switch 80 came into its fifth position it was assumed that the connecting circuit 17 had been connected to the operator's telephone and had associated therewith a registering and controlling equipment by the switch 29 individual to such connecting circuit in the well-known manner. This was assumed for the reason that since the switch 29 and the sequence switch 90 are generally of similar construction, the sequence switch 90 having made a complete revolution, the switch 29 had in the same time found and seized an idle registering and controlling equipment, since it had been assumed that the operator to which such registering and controlling equipments are individual was idle.

Assuming now that for some reason the operator is delayed in attending to her duties relating to a call extended to her position and that when the subsequent call reaches her position the switch 29 continues in operation hunting for an idle registering and controlling equipment and the operators telephone equipment, which in the usual manner would be associated therewith if the operator was idle, the relays 27 and 28 are so adjusted that when a single switch 29 is connected in series therewith, the relay 27 alone will be energized. Therefore, although the sequence switch 80 will pass through its positions 5, 6 and 7 the relay 28 being deenergized, when it comes into position 8 no circuit is established for its own motor magnet but a circuit is established for the sequence switch 90 over sequence switch contact 86 bottom, armature and front contact of the relay 27, and sequence switch contact 92 top. This causes the sequence switch 90 to make a complete rotation and in passing through its position eighteen drives the sequence switch 80 into its ninth position over the circuit including sequence switch contact 86 bottom, front contact and armature of the relay 27, and sequence switch contact 92 bottom. At this time, if the previous call has been connected to an idle registering and controlling equipment, relay 27 will be deenergized and the timing apparatus will again operate in the usual manner. On the other hand, if such is not the case, the sequence switch 90 will start on another complete rotation over the circuit previously traced, including the front contact and armature of the relay 27 and in passing through its eighteenth position will drive the sequence 80 into its tenth position. From position 10 of the sequence switch 80 the normal operation of the timing apparatus is resumed and when, as before, the sequence switch 80 has been moved out of its twelfth position, the sequence switch will be restored to normal to remove the busy guard from this operators position. It will be observed that in the case just described, the normal period measured by the timing apparatus has been extended by the time occupied by one or two revolutions of the sequence switch 90, as may be required under the particular circumstances which exist at this operators position.

If, even after the prolonged interval, for which the operators position is maintained busy, just described, a further call should be extended to such operators position, and at that time there should exist two calls, neither of which have as yet been extended to an idle registering and controlling equipment, two switches such as 29 will be connected in parallel in series with the relays 27 and 28. In this case the operation as previously described of the timing apparatus will take place in positions 1 to 4 of the sequence switch 80, but since relay 28 is now energized as well as relay 29, the sequence switch will stop in its fifth position and the sequence switch .90 will be caused to make acolnplete revolution while such sequence switch 80 is in its fifth position by the circuit including the sequence switch contact SGtopand the armature and front contact of the relay 28. On the completion of this revolution of the sequence switch 90, the sequence switch 80 will be driven into its sixth position where it will cause a further complete revolution of the sequence switch 90 as it comes into its first position by the establishment of the same circuit. When the sequence switch 90 is again passing through its eighteenth position, the sequence switch 80 will be driven out of its sixth position into its seventh position, in which position a further revolution of sequence switch 90 takes place, after which the sequence switch 80 comes into its eighth position when the control passesto the relay 27 and the further operation of the timing apparatus takes place as has been described.

It wasassumed that when the sequence switch 80. came into its sixth and seventh positions there were still two switches 29 hunting for an idle registering and controlling equipment, and therefore connected in the same circuit with the relays 27 and 28, causing the relay 28 to be energized. Therefore, the time for two further additional revolutions was inserted in the predetermined interval for which the operators position was maintained busy under the circumstances set forth.- If at this time, however, on the contrary one of these switches 29 had connected the call associated therewith to an idle registering and controlling equipment, the relay 28 would have fallen off and the sequence switch 80 would have passed directly into its eighth position, andone or two of the revolutions of the sequence switch 90 would have been eliminated.

It will, therefore, be seen that if two calls have been extended to an operators position, neither of which have as yet reached the operator, the operators position will not only be maintained busy for the normal period plus the period required for the two revolutions of the sequence switch .80 caused by the energization of the relay 27, but will be maintained busy for the further period required by the one, two or three revolutions of the sequence switch 90,,as the case may be, due to the energization of th relay 28in the fourth, fifth and sixth, or fifth, sixth and seventh positions ofthesequenceswitch 80.

In rsum it will be seenthat under normal conditions upon the receipt of a call, the operators v for a perio say of four seconds, after which time another callmay be extendedm her. ,0- sition. If, however, a call has been exten ed to her position-which has not as yet been connected toihfirgquipment, the test guard position. will be maintained busy will be maintained upon the position an increased interval which may even be as much as seven seconds, and if two calls have been connected to such operators position, neither of which have as yet been extended to her equipment, the interval may be further extended to so much, for example, as eleven seconds.

It will, of course, be understood that the time intervals referred to are given for example only and that by the rearrangement of the circuits in an obvious manner, the period of time elapsing in the normal operation of the timing apparatus or in either of the abnormal cases mentioned may be so modified as the traiiic conditions of the articular exchange in which the apparatus 1s used may require. Generally, it will probably be found that if the time occupied by the timing apparatus in its normal operation is about seventy-five per cent of the time normally required by an operator to complete her duties with regard to the average call, a considerable saving will be accomplished with a minimum delay to incoming calls.

What is claimed is:

1. In a call distributing system, means for selecting an operators position and extending a call thereto, means at such position for establishing connections between calling and called lines, and means independent of such connecting means for rendering the position busy to subsequent calls for a normal predetermined time interval after the distribution of a call thereto, and means dependent upon the condition of such connecting means for rendering the position busy for a further predetermined interval.

2. In a call distributing system, means for distributing calls to an operators position in combination with timing means at said position for automatically determining the normal rate at which such calls may be distributed to such position, and means dependent upon the condition of such connecting apparatus for automatically altering such rate of distribution.

3. In a call distributing system, means for distributing calls to an operators position, means for associating such distributed calls with connecting circuits at such position, controlling apparatus adapted to be associated with such connecting circuits, a timing device at such position adapted to intro.- duce a time interval between the distribution of successive calls of the connecting circuits at such position, and means controlled by the operative condition of the controlling devices associated with the connecting circuits at the position for modifying the operation of such timin device.

4. In a call distributing system, means for distributing calls to an operators position, means for associatin such distributed calls with connecting circuits at such position, automatic means for selecting and associating a controlling equipment with connecting circuits to which calls have been distributed, means at said position for introducing a time interval between the distribution of successively calls to such connecting circuit, and means controlled by the number of controlling equipments which are simultaneously in operation for determining the extent of such time interval.

5. In a call distributing system, an operators position, connecting circuits at such position, calling lines, means for selecting such position and extending such calling lines to such connecting circuits, a plurality of controlling equipments, automatic switches for selecting and connecting such controlling equipments to connecting circuits taken for use, means for maintaining such position non-selectable to calling lines for a definite time interval after the extension of a calling line to a connecting circuit, and means dependent upon the number of automatic switches simultaneously operatin to select controlling equipments to determlne the extent of such time interval.

6. In a call distributing system, an opera tors position, connecting circuits at such position, calling lines, means for selecting such position and extending such calling lines to such connecting circuits, controlling equipments adapted to be associated with such connecting circuits, equipment selector switches adapted to select idle controlling equipments and associate them with connecting circuits to which calling lines have been extended, a sequence switch adapted to be moved from normal each time a calling line is extended to a connecting circuit at the position to render the position non-selectable to calling lines, a timing device for returning such sequence switch to normal to render the position selectable after a time interval, and marginal relays included in the operating circuit of the equipment selector switches for determining the duration of said time interval.

In witness whereof, I hereunto subscribe my name this 2nd day of March A. D.. 1917.

LIPA POLINKOWSKY.

copies of this patent may be obtained for live cents each, by addressing the "Commissioner of intents,

Washington, D. 0." 

